Parrot's feather is a semi-submerged aquatic weed that grows in coastal waterways of eastern Australia. It is native to South America and widespread around the world. It can form dense stands within a waterbody, impeding water flow and altering natural habitats.
Parrot's feather occurs in coastal areas from Brisbane to Sydney.
In Australia, parrot's feather spreads by fragments. Male and female flowers are produced on separate plants. Only female plants have been found in Australia, and therefore seeds are not produced. If male plants were introduced to Australia, this species could become more prolific.
Parrot's feather is a feathery submerged water plant, with some stems above the water (emergent). It has whorls of feather-like leaves. The submerged leaves are up to 4 cm long, while the emergent leaves have a blue-green appearance, are toothed, 2.5-3.5 cm long, and crowded at the tips of stems.
The flowers are inconspicuous, and occur in the leaf axils (the junction between the stem and the leaves) on emergent stems.
Stems are spreading, erect and hairless.
Similar looking species include ambulias (Limnophila spp.), cabomba (Cabomba caroliniana) and other Myriophyllum species.
Parrot's feather grows very well in nutrient-enriched water, in still or slow-moving bodies of fresh water in coastal areas of eastern Australia.
New South Wales Industry & Investment (2009) Recognising Water Weeds - Plant Identification Guide, Orange.
Physical removal is recommended where appropriate. Draining a waterbody and allowing the parrot's feather to dry out can afford control. Contain infestations wherever possible to avoid further spread resulting from the movement of plant fragments.
Parrot's feather (Myriophyllum aquaticum) is not declared in NSW under the Noxious Weeds Act 1993.